6x47 lapua trim length ?

[cooperman223]

I have just bought some once fired? 6x47 lap brass,
the guy that i have bought it from says its not been trimmed,
some of the casses still have the primer in and have not been re-sized, however,
most of the casses measure 1.836 this seem short compared to case length drawings.
What measurement are you getting from your brass ???
I suspect they have been trimmed.
thanks.

 

[cooperman223]

Thanks for the reply,
i have gone through the cases,
the smallest is 1.834 the longest 1.839
I can borrow a case trimmer this week from a friend,
it looks like they need standardizing.
All the necks are equal at .272
thanks

 

[Cheechako]

cooperman

If you have only .005' difference between the shortest and longest case you shouldn't agonize over trimming. A lot of work for little, if any, gain. They're already too short. I'd wait until they are fired at least once more each. Of course, if it makes you feel better . . .

Rewinder - How come the brass will shorten when necked down? It usually works the other way.

Just curious.

Ray

 

[larosa]

cooperman my necked down and once fired brass measures 1.840 inches, so you should hold off on your trimming for a while.

 

[cooperman223]

Thanks lads, i was going to trim all to same length, but like has been said i think its best to batch them to length, shoot them and see how they perform, it looks like they they have been trimed a bit short even though the chap i bought them from says not
thanks
john.

 

[fdshuster]

cooperman223: I have and use the Sinclair chamber length gages and determine the actual chamber length, it is recorded, and I will let the cases stretch, those that do), to within .010'. Depending on the chambering reamer that was used, I've measured chamber lengths that were as much as .042' longer than max case length, and this is the 'gap' in front of the case mouth that will quickly fill-up with a ring of carbon.

 

[cooperman223]

Thanks Frank, thats worth investing in, i can see it will come in very handy.
john.

 

[fdshuster]

john: Yes, they are a worthwhile 'gage', cost being around $7.00 for each caliber, they are re-usable, and I 'sacrifice' a case that is nearing the 'end-of-life', so it doesn't hurt as much as it would if it were a new Lapua. I could not believe how much longer chamber lengths sometimes are: have a 222 Rem. that has a chamber length of 1.742' for a max case length of 1.700'-- must be a 'lawyer thing' for those who never measure & trim cases. If you follow the 'advice' in most loading manuals and trim .010' shorter than max, an even longer gap is being created, for no good reason.